A manual order-check workflow uses a Pub/Sub pull subscription to deliver orders to sales agents. You must prevent processing an order twice by different agents without adding workflow complexity. What should you do?

Using Pub/Sub's exactly-once delivery feature on your pull subscription is the most straightforward and effective solution. This feature, when enabled, ensures that each message is delivered and processed successfully by a subscriber exactly one time, preventing duplicate processing by different agents without requiring complex custom logic. A Deduplicate PTransform in Dataflow would involve additional infrastructure and processing, adding complexity. Creating a transactional database to monitor pending messages would also introduce significant architectural overhead and management. A new Pub/Sub push subscription to monitor processed orders wouldn't prevent duplicate processing at the point of delivery; it would only track what has already been processed, potentially after a duplicate has occurred.